* Can we create any games type/style or sometime the engine limit yourself ?
Most of the time, the limit comes from the user.
Also there are still some advice to follow to have game working nicely.
Best Practices
Performance tips
Memory usage
* Can we create multiplayer games with nodeJS ?
Yes, the Websocket object allows you to communicate with nodeJS servers.
On the other hand, the Multiplayer object relies on WebRTC, a different technology.
* It is the good choose for my profile ?
Actually you are the one to answer that question by testing the free version.
If you enjoy it and find yourself comfortable with it, no reason that the complete edition does not fit your needs.
* Can we add in-game purchases & admob in your mobile game ?
How to use AdMob and IAP official plugins on Android Crosswalk/XDK
* The visual scripting editor work well (UE4 make me love visual scripting) ?
I haven't tried UE4 so I don't know how it fairs in comparison.
Again, better test the free version to answer that one.
I've been using C2 since it was publicly available, and yes, the editor works nicely for me.
Also : http://www.construct-french.fr/